Cover Story: Wireless Revolution

A talking bus? Get up to speed on modern wireless diagnostics.

“When the bus comes into range of an antenna in the service lane, it’s automatically doing a health inspection of that vehicle,” he explains. “Number one, it’s checking to make sure the AVM system is operating—it does a health inspection of itself! Then it goes through the various checks: engine parameters, transmission parameters, heating, ventilation and air conditioning, door system functionality and brake pushrod travel.

“If one of those criteria isn’t met, when the cleaner gets back in the bus to park it, the Voice Annuciator will tell that individual that the bus requires a maintenance action,” Wallace explains.

The maintenance action is then flagged in the work control center, so the cleaner will know not to let the bus go back out. At the same time, the maintenance department is notified that they have a bus that needs work before it can be put back in service.


Although it didn’t start out that way, the Clever Devices IVN® (Intelligent Vehicle Network) controller has become an all-purpose tool for transit fleets like WMATA—sort of a Swiss Army knife for fleet managers.

“What IVN® is, in general, is a controller on the bus that does multiple things,” explains Clever Devices’ Saporita. It began with the Voice Annunciator, he explains, then was modified to include a passenger counting function, which counts boardings and alightings, so transit agency operations can manage usage and service levels.

“So, we have this platform on the bus, and we came up with this concept for AVM,” says Saporita. “There are all these networks on the bus, and we tied our controller into those networks, and any system that was tied into that network, we could then capture data from them in real time, store it, and when the bus gets back to the depot we can upload it via a wireless connection.

“That data goes to a database, and we have a software product, called the AVM client, that displays and reports that information to the maintenance people, via automatic reports that are printed out and via E-mail as well,” he says.


When AVM was developed in the late ‘90’s, only the engines and transmissons were intelligent enough to create data that the system could gather and report. Since then, more and more intelligent systems have been put on buses, but the Clever Devices engineers don’t always wait for the bus engineers to get up to speed.

“One thing WMATA did that was really ahead of its time concerned a problem they had with their doors,” recalls Saporita.

“The door systems on buses are notoriously un-intelligent. They don’t have a lot of processing ability,” he says. “So, we added these custom solutions to the AVM product where we would actually time how long it took for the door to open and close.”

Now WMATA could monitor those signals and check the times, and if they perceived that a door was taking too long to close, or was opening too fast, AVM would generate a fault that would be sent to the maintenance people when the bus came back to the depot.

“So, there are two things we’re doing,” Saporita explains. “We’re monitoring the intelligent systems that are already there, like the engine, and there are other systems that are not intelligent that we provide intelligence to. We generate faults ourselves, based on data that we get into our controller.”


“We’re learning different things and new ways to use the system day in and day out,” Wallace admits. “Now, initially, if you don’t go slow but sure, you can be overwhelmed with the amount of information that you get.”

That’s exactly what happened when the buses started talking. During the pilot program, Wallace and his staff went through “an arduous process” of weeding out unimportant, irrelevant and even erroneous fault codes, and building filters into AVM to tighten the monitoring parameters.

“We have one sub-fleet of buses—the New Flyers that we call ‘the vacuum cleaners’—their cooling sytems are very robust, and at no charge we sweep the streets of Washington D.C,” Wallace says. “They suck it all up into the radiator!

“Now, a Cummins 8.3 gas engine is set up to give you an indicator light at a certain temperature, and a shut-down at a certain temperature,” he explains. “Well, when the bus comes into the service lane, we’ve got it set up so that, about 12 degrees prior to getting that light, it’s going to tell us, ‘Hey, you need to check the radiator in this bus, because if you don’t, tomorrow it’s going to run hot.’”

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